Apparatus for circulating drilling fluid in rotary drill



March 26, 1957 v. c. MICKLE 2,786,651

APPARATUS FOR CIRCULATING DRILLING FLUID IN ROTARY DRILL Filed 001,. 21, 1953 2 Sheets-Sheet l INVEN'TOR. Virgil C. M/ck/e.

VJMMMQ A T TORNE YS.

March 26, 1957 v. c MICKLE 2,786,651

APPARATUS FOR CIRCULATING DRILLING FLUID IN ROTARY DRILL Filed Oct. 21., 1953 2 Sheets-Sheet 2 IN V EN TOR.

V/rqfl C. Mick/e.

A TTORNE Y5.

United States Patent APPARATUSFOR CIRCULATING DRILLHJG FLUIDIN ROTARY DRILL Virgil. C. Mickie, Enid, kla., assignor to George E. Fai ing Company, Enid, Okla., a corporation or Delaware Application October 21, 1953, Serial No. 387,483

4 Claims. (Cl. 255-24) This invention relates to a rotary drilling apparatus and in particular to a method and apparatus for circulating drilling fluid.

It is well known that in rotary drilling of a well into the earth, a drilling fluid is circulated under pump pressure through the drill pipe to wash cuttings made by the drill bit to the top of the bore hole. The fluid containing the cuttings over-flows from the bore hole and is collected in a pond where the cuttings settle out and the fluid, free from cuttings, is re-circulated under pump pressure.

Where circulation is downwardly through the drill pipe and upwardly through the bore hole, the cuttings are. washed into the; formation through which the well is drilled and, often the cuttings plug the producing sands. Also, underground cavities and cave-ins result in lost circulation and velocities so that. the cuttings are apt to settle out and not be effectively removed from the bore hole.

The above, difficulties are overcome in part by reverse circulation, that is, the water from the pond flows down- Wardly through the bore hole and is pumped upwardly through the drill pipe by means of a pump which discharges into, thev pond. The bit, however often loosens large fragments or boulders, which are elevated due to the high velocities of the well fluid. Consequently the large fragments and boulders contained in the drilling fluid are destructive to the pump. It is therefore a principal object ofthe present invention to provide a method and apparatus for effecting upward circulation through the drill pipe without passing the cuttings, large fragments, and boulders through the pump.

Other objects of the invention are to provide asimple and inexpensive circulating apparatus for eifecting substantially high velocity upward flow of the drilling fluid and. thereby facilitate removal of the cuttings and. materials loosened by the drill b-it, to provide a circulating apparatus wherein only clean fluid is passed through the pump. and discharged under high velocities through a jet eductor which is connected with the drill pipe. for eflecting withdrawal of the drilling fluid at velocities suflicient to effect discharge of the cuttings and solid materials, to provide an apparatus which is especially adapted. for portable drilling apparatus, and to provide for regular circulation when desired.

In accomplishing these and other objects of the invention, as, hereinafter pointed out, I have provided an improved structure, the preferred form of which is illustrated in the accompanying drawings, wherein:

Fig. l is a perspective view of a portable drilling apparatus equipped with a circulating mechanism embodying the features of the present invention.

Fig. 2 is an enlarged longitudinal section through the ejector and the tubular body member that is connected. thereto for discharge of the drilling and pressure fluids.

Fig. 3 is an enlarged section through the jet eductor and a portion of the tubular body member.

Fig. 4 is a section through the eductor head on the.

2. line 4-4 of Fig. 3, looking in the direction of the nozzl'e jets.

Fig. 5 is a similar cross section on the line 5-5 of Fig. 3.

Referring more in detail to the drawings 1 designates a drilling apparatus which may be of the portable type in that it includes a motor driven vehicle 2, having a bed or platform 3, on which the drilling apparatus is mounted. The drilling apparatus includes a power unit such as an internal combustion engine 4, that is mounted on the' platform 3, and drives a winding drum 5, a turntable 6, and a pump 7. The winding drum and turntable are connected with the power output shaft 8', by suitable driving connections standard to this type of rig. In the illustrated instance, the drive for the pump 7 is by means of a chain 9, operating over a sprocket 10 on the shaft 8, and a sprocket 11 on the pump 7.

Also carried on the vehicle is a derrick 12 that is adapted to be moved from a horizontal position on the vehicle to an erect position as shown in Fig. l. The top! of the derrick (not shown is provided with the customary crown pulleys for passing a line 13 from the winding drum 5, the line 13 being used for supporting and. handling the drilling pipe 14, as is Well understood by those skilled in the drilling art.

The drill pipe 14 carries a drill biton the lower end thereof (not. shown), that is rotated by means of the turntable 6 to.- extend the bore hole into the earth formation as when. drilling for water or minerals such' as oil and gas. The drill pipe 14 includes joints of pipe that are inter-connected by tool joints so that additional joints may be added. thereto-progressive with the drilling operation. A driving connectionis effected between the drill pipe and the rotary table by means of at Kelly rod- 15 that is connected withthe upper end of the drill pipe and carries a swivel head 16. The swivelhead. 16 is equipped with a bailv 16 that is connected with the line 13. through, a tackle 17 and. the traveling block hook 18. Connected, with the swivel head 16 and depending therefrom is. a flexible conduit or hose 19, through which drilling fluid is drawn from the drill pipe by means of an. eductor 20 forming a part of the present invention. The eductor 2G is preferably mounted on the platform 3,. for example as illustrated in- Fig. l.

The eductor 29 includes a head 21 that is connected with the hose 19 through a nipple 22. and has a coaxial and elongated tubular body member 23-, having an elbow 24 at the discharge end thereofv for directing the ejected fluid, cuttings, boulders and other solid materials into a pond 25, later to be described.

The eductor head 21 includes an annular Wallportion 26, which is preferably of larger diameter thanthe nipple 22, the nipple being connected therewith. byan annular end Wall 27. The opposite end of, the wall- 26- connects wi'th a nozzle 23. The nozzle 28 has. an. annular wall 2?- converging in the axial direction of the head to provide a smaller discharge opening, 36,. in alignment Withthe tubular body member 23. Encircling the outlet 36 of the nozzle 28 is an outwardly and, forwardiy flaring flange 31, that cooperates with a rearwardly spaced. annular flange 32 of the nozzle and an outer circumferential wall 33 in forming an annular chamber 34 surroundingthe nozzle 28. The chamber 34 has a lateral. inlet 3:3 for connecting a pipe 36, by which a high pressure educh mg fluid" is discharged into the chamber 34 for. distribution at high velocity and discharge through a plurality of jet nozzles 37 that are arrangedin circular series about the. outlet 30 0f the nozzle 28. The jet nozzles 37 may be of any conventional type capable of discharging jets of: the, high pressure fluid inimpinging relation and forwardly of the. nozzle to form a vacuum or suction on the drilling fluid in the drill pipe from the upper end so that the entire column of fluid in the drill pipe moves upwardly under high velocity and i discharged with the jetting fluid through the tubular body member 23. The jet nozzles are preferably removably mounted in the flange 31 and therefore have threaded necks 38 that are engaged within internally threaded openings 39 of the flange as best shown in Fig. 3.

The elongated tubular body member 23 is connected with a hollow frusto-conical or funnel-shaped inlet member 40 that is carried by an annular ring 41 secured to the peripheral portion of the flange 31 by fastening devices such as cap screws 42 that have shanks extending through suitable openings 43 that are provided in the annular flange 31 as shown in Fig. 3. The funnel-shaped inlet 40 connects with a reduced portion 44 which provides an elongated cylindrical mixing chamber to pro vide commingling and high velocity agitation of the drilling fluid drawn through the nozzle 28 and the pressure fluid which is discharged through the jet nozzles 37. The opposite end of the elongated tubular body member has an elongated outwardly flaring discharge portion as indicated at 45, to connect with the elbow 24.

The pipe 36 extends upwardly and forwardly above the elongated body member 23 and carries a T fitting 46, the T fitting 46 being connected with the outlet 47 of the pump 7. Also connected with the T fitting 46 is a pipe 48 that extends across to the opposite side of the vehicle and connects by means of a stand pipe 49 with a swivel head 50 on a Kelly rod 51. The Kelly rod 51, while not in use, is supported within the derrick and is adapted to be connected with a drill pipe 14 upon removal of the Kelly rod 15. The pipes 36 and 48 are provided on the respective sides of T fitting 46 with shut off valves 52 and 53, respectively, whereby the discharge from the pump may be directed through either one of the pipes depending upon the type of circulation desired.

The pump 7 has an inlet 54 that connects, by means of a suction hose 55, with a clean fluid pond or basin 56. The ponds 25 and 56 may be formed in the ground alongside of the vehicle at the site of the drilling operation and inter-connected by a weir substantially at the level of the liquid collecting in the pond or basin 25 whereby the settled liquid from the pond 25 is passed over the weir 57 into the pond 56, the cuttings and solids having settled to the bottom of the pond 25. A part of the liquid, free of solid materials, flows from the pond 25 through a flow duct or trench 53. The bore hole is thus kept full of liquid to replace the liquid Withdrawn from the drill pipe.

Assuming that the drilling apparatu is set up at the site where a bore hole is to be drilled, the derrick is erected and a pond is provided alongside the platform 3 and in a position to receive discharge from the elbow 24. The pond 56 is provided near the pond 25 and connected by the weir 57. The suction hose 55 is placed in the pond 56 and both ponds are filled with drilling fluid.

The bit is attached to the lower end of the kelly 15. With the kelly extending through the turntable 6 and with the swivel head suspended from the crown pulleys by means of the line 13. the Kelly rod is rotated to start drilling of the bore hole 59.

A trench or duct 58 is provided between the pond 25 and the bore hole 59 so fluid flows from the pond 25 into the bore hole. The ponds form the source of supply for the drilling fluid. If there is not sufficient fluids entering the bore hole from the formation being drilled to keep the ponds full, additional fluid must be added as the bore hole deepens.

A the hole progresses, joints of the drill pipe are inserted between the bit and the Kelly rod. The drilling fluid flows from the pond 25 into the bore hole and establishes a hydro-static head of fluid exteriorly of the drill pipe and a corresponding head rises within the drill pipe to elevate the cuttings made by the bit. It is obvious that the upper end of the drill pipe and the hose depending from the swivel head form the legs of a siphon to continue the flow of the drilling fluid upwardly through the drill pipe. However, the siphon must be started and the fluids must be moved at substantial velocities to provide the carrying force necessary to lift the cuttings and any rock fragments or boulders loosened by the bit. This force is provided by the pump 7.

With the pump 7 in operation, fluid, free from cuttings, is drawn from the pond 56 by way of the hose connection. 55 and discharged at high pressure through the pipe 36 and into the manifold chamber 34 of the cductor head, from where the fluid is discharged at high velocities through the jet nozzles 37 into the funnel-shaped inlet 40. The velocity discharge of the jet nozzles 37 draws a vacuum within the head 21 of the cductor 20 to effect movement of the drilling fluid upwardly of the drill pipe and through the Kelly rod 15, swivel 16 and downwardly through the hose connection 19 where the drilling fluid is discharged into the inlet portion of the elongated tubular body member to be picked up by the flow from the high velocity jet nozzles 37 and carried into the elongated cylindrical mixing chamber which is provided in the portion 44 to provide comrningling and high velocity agitation of the drilling and pressure fluids for discharge of the drilling and pressure fluids through the flared expansion chamber and elbow 24- into the pond 25. With this arrangement, suflicient suction is provided to start the flow and to maintain the flow throughout the height range of the siphon even when customary lengths of drill pipe are used. Thus a constant circulation is maintained downwardly through the bore hole and upwardly through the drill pipe at suflicient velocity to carry the cuttings and any fragments or boulders removed by the bit, upwardly through the drill pipe for discharge through the eductor.

After discharge into the pond 25, the cuttings, rock fragments, and sludge settle to the bottom of the pond and the drilling fluid, free of such material, flows over the weir into the pond 56. Also, a part of the liquid flows from the surface of the pond through the trench 58 and into the bore hole. As the drilling progresses, the Kelly rod moves downwardly through the turntable 6 and it becomes necessary to add another section of drill pipe to continue deepening of the bore hole. This is effected as in standard practice by withdrawing the Kelly rod until the tool joint connection thereof with the first joint of drill pipe appears above the turntable. The drilling string is then supported by the turntable and the Kelly rod is disconnected therefrom. Another joint of drill pipe is then brought into position and connected with the string of drill pipe, after which the entire string of drill pipe is lowered into the bore hole until the coupling on the added stand of pipe is in position for connecting the Kelly rod. The Kelly rod is then reconnected with the tool joint and the drilling string lowered to again bring the Kelly rod into position to be rotated upon operation of the turntable. It is obvious that the flow of drilling fluid is suspended every time a new section of drill pipe is added to the drilling string, and that disconnection of the Kelly breaks the siphon. It is also obvious that when recirculation is to be started the siphon comprising the Kelly rod and hose 19 is in its highest position, however by reason of the elongated tubular body member additional suction is provided to start the siphon effect of the drilling fluid without the necessity of a secondary priming fluid. The eductor also produces the suction necessary to continue the flow of the drilling fluid solely by the manner of discharging the mixed fluids through the chambers of the elongated tubular body member.

With the circulation downwardly through the bore hole and upwardly through the pipe, ample velocity of the fluid is maintained to assure upward movement of the cuttings and the like so that even though the formation may be highly porous, have cavities or cave-ins, there is no drop in velocity of the fluid circulated through the drill pipe. It is also obvious that a high lifting force is effected without passing the rock fragments, boulders, and the like, through the pump.

If for some reason conventional circulation is desired, the Kelly rod 51 may be substituted for the Kelly rod 15. The valve 53 is opened and the valve 52 is closed so that when the pump is started, the flow is through the pipe 48, stand pipe 49, and swivel head 50 and downwardly through the drill pipe for return flow through the bore hole.

What I claim and desire to secure by Letters Patent is:

1. In a drilling apparatus for drilling bore hole from the surface of the ground to substantial depths below said surface and which includes a drilling string composed of customary lengths of intercoupled drillpipe, a Kelly rod connected with the upper drillpipe, a swivel head on the upper end of the Kelly rod, a bit on the lower end of the drillpipe, means for rotating the Kelly rod to turn the drill bit for deepening the bore hole, means connected with the swivel head for lowering the drilling string with deepening of the bore hole and for raising the drilling string when disconnecting the Kelly rod for adding another joint of drillpipe and for lowering the drilling string to engage the Kelly rod with said rotating means to continue the drilling of the bore hole, a hose connected with the swivel head and forming the down-leg of a siphon of which the Kelly rod constitutes the up-leg, an eductor connected with the down-leg of the siphon, means for supporting the eductor in substantially fixed position, a pump, means connecting the pump to the eductor for supplying a fluid under pressure to the eductor to be discharged therefrom for furnishing energy to lift the drilling fluid and cuttings carried therewith through the siphon, an elongated tubular body member connected to the discharge of the eductor, said body member comprising an inlet portion attached to the discharge end of the eductor, and an elongated outwardly flaring discharge portion forming the other end of the body member and providing an outwardly flaring expansion chamber, whereby an elongated mixing chamber is provided in said elongate-d body member to provide commingling and high velocity agitation of the drilling and pressure fluids and whereby discharge of the drilling and pressure fluids is effected through the flared expansion chamber.

2. A drilling apparatus as described in claim 1 wherein said connection of the inlet portion of the elongate-d tubular body member is a hollow frusto-conical member having the large end thereof encircling the discharge of the eductor and the small end connected with the inlet portion of the elongated tubular body member.

3, A drilling apparatus as described in claim 1 wherein said eductor includes a head having an inlet in connection with the down-leg of the siphon, a nozzle in the head for directing the drilling fluid through the discharge of the eductor and coaxially of the elongated tubular body member, said head having a passageway extending around the nozzle and being connected with the means which supplies the pressure fluid to the eductor, and jet nozzles having connection with said passageway and discharging in the direction of the inlet portion of the elongated tubular body member.

4. A drilling apparatus as described in claim 1 wherein said eductor includes a head having an inlet in connec tion with the down-leg of the siphon, a nozzle in the head for directing the drilling fluid through the discharge of the eductor and coaxially of the elongated tubular body member, said head having a passageway extending around the nozzle and being connected with the means which supplies the pressure fluid to the eductor, and jet nozzles having connection with said passageway and discharging in the direction of the inlet portion of the elongated tubular body member, and wherein said connection of the tubular body with the discharge of the eductor consists of a hollow frusto-conical member the large end of which is connected with said head of the eductor circumferentially of the jet nozzles and the small end connected with the inlet portion of the elongated tubular body member.

References Cited in the file of this patent UNITED STATES PATENTS 199,640 Haas et al. Jan. 29, 1878 640,463 Gildea Ian. 2, 1900 987,266 Smith Mar. 21, 1911 1,461,240 Godfrey July 10, 1923 1,806,287 Forrest May 19, 1931 2,127,728 Grant Aug. 23, 1938 2,485,098 Johnson Oct. 18, 1949 2,715,016 Veneziani et a1, Aug. 9, 1955 

